Speed-indicator



(No Model.)

A.' L. PARCELLE.

' SPEED INDICATOR.

No. 586,318. l Patented July 1'3, 1897.

@#0202 eys.

UNITED STATES PATENT OFFICE.

ALBERT L. PARCELLE, OF BOSTON, MASSACHUSETTS.

SPEED-INDICATOR.

SPECIFICATION forming part of Letters Patent No. 586,318, dated July 13, 1897.

Application filed December 18l 1896. Serial No. 616,129. (No model.)

To all whom. it may concern.;

Be it known that I, ALBERT L. PARCELLE, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Speed-Indicators, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention consists in a speed indicating or measuring device of simple, durable, and novel construction or character, the said device being adapted to be attached to or used in connection with shafting or machinery having a rotary motion to indicate the speed of revolution or in connection with the wheel or axle of a vehicle of any description-such, for example, as that of a bioycle-to indicate the rate of speed at which the vehicle is travcling. It is of a character which enables it to work easily and without interfering at all with the easy running of the bicycle. It is constructed with the utmost degree of simplicity, has exceedingly little liability to wear, and is not liable to have its normal operation disturbed by jolting, so as to indicate temporarily a false rate of speed.

The invention will be described first with reference to the accompanying drawings, in which I have represented the best embodiment thereof that I have yet contrived, after which the distinguishing characteristics of the invention will be particularly pointed out, and distinctly defined in the claims at the close of this specification.

Figure 1 of the drawings is a view of the said embodiment of my invention, the parts thereof being mainly in vertical section on' the dotted lines l 1 of Fig. 2. Fig. 2 is a view showing the said embodiment in elevation, looking from the right in Fig. 1. Fig. 3 is a view in section along the line 3 3 of Fig. 1, looking from the right in the latter iigure. Figs. 4 and 5 are views in detail, showing a modification, Fig. 4 being sectional.

At l is a suitable case, and at 2 is a tubular support for the said case, only a portion of the said tubular support being shown.

At 3 is a glass cover having a suitable lnetallic rim 4, the iiange of the said rim entering the top of the case l, as shown most clearly in Fig. l. Any suitable form, construction, or character of case, support, and cover may be employed, according to the taste of the maker andthe requirements of the use to which the device is to be applied.

At 5 is a small rod 0r spindle which is located within the support 2. In practice the said rod or spindle is driven by or from the rotating part which is to have its speed ascertained or indicated. The driving of the said rod or spindle by or from the said rotating part may be effected in any known or suitable manner, not necessary to be shown or described herein.

6 is a disk mounted upon the said rod or spindle 5 and turning therewith, the end of the said rod or spindle projecting beyond the said disk.

7 is a small segment-gear located at the side of the disk G, it tting loosely upon the end of the rod or spindle 5.

8 is an inclined cam which is formed or ixed on the side of the said gear 7.

9 is a reversely-placed inclined cam, the face of which bears against the face of the cam 8. This inclined cam 9 is connected with the rod or spindle 5 in a manner which causes it to rotate in unison with the latter, while leaving it free to move lengthwise thereof. Any suitable or known means may be employed to this end.

In the drawings I have shown the rod or spindle 5 as slabbed away at 10, (see Fig. 4,) the cam 9 having a pin 11 passed therethrough and the said pin engaging with the flat surface which is produced on the rod or spindle.

At 12 is an arm which is pivoted to the disk 6 near the edge of the latter, as at 13, Fig. 3, the said arm being provided with a gear-segment 14, that engages with the segm ent-gear 7. It is provided also with a curved spur or projection 15, the convex face of which receives the pressure of one end of the flat spring 16, the opposite end of the latter being secured to the disk 6, as shown most clearly in Fig. 3.

17 is a movable or yielding arm which in the drawings is shown as consisting of a flat spring, it being connected at one end thereof to the case l, as by means of a screw 18. (See Fig. 1.) At or near its mid-length the said arm 17 rests against the top of the cam 9 and IOO its free end enters an inclined or spil-allyformed slot 19 in the hub 20, which latter is .pivoted on the interior ofthe case, as by means the zero position of the index or pointer 22, y

that is shown in Fig. 2. When the spindle 5 and disk 6 are rotated, the weighted portion of the arm 12 is urged outwardly from the axis of rotation by the cen trifugal force which is generated in consequence of the said rotation, the tendency of the free end thereof to move outward being opposed, however, by the action of the spring 16 upon the arm 15, As the arm 12 swings outward its gear-segment 14E rotates the segment-gear 7 relatively to the disk 6 and spindle 5, thereby causing a rotative movement of the cam 8 relatively to the cam 9. The action of the cam S against the cam 9 causes the latter to move in the direction of the length of the rod or spindle 5, thereby moving the arm 17. The movement of the free end of the said arm 17 in the inclined or spiral slot 19 of the hub 2O causes the said hub to turn upon the pivotal screw 21 and swings the index or pointer 22, the extent of the movement of the said index or pointer being indicated by the graduations of the scale 23. The sprin g 16 causes the arm 12 and segment-gear 7, with its cam S, to return toward their normal positions as the speed of rotation slackens,'while the resiliency of the arm 17 acts to hold cam 9 pressed against cam 8 and to return the index or pointer 22 toward its normal position at the zero end of the scale 23. In the normal position of the parts shown in Fig. 3 the free end of the spring 16 acts upon the inner portion of the convexly-curved surface of the spur or projection 15 of arm 12. As the arm 12 swings outward under the influence of centrifugal force this movement of the said arm brings successively into contact with the spring16 the portions of the curved surface of the spur or projection 15 which are farther and farther removed from the pivotal point of the arm 12 and nearer and nearer to the fixed point of the spring 16. Thus the spring 16 becomes more and more effective in its action upon the spur or projection 15, partly because of the decreased leverage which is secured in the manner just stated and partly because the said spring becomes in effect shorter and shorter and hence opposes an increasing resistance to the movement of arm 12. In this way as the weighted inner or free end of arm 12 is caused to pass farther and farther away from the axis of rotation iu the manner hereinabove described and as the centrifugal force is increased in consequence of the said movement away from the axis of rotation the resistance offered by the spring to the outward movement of the arm is correspondingly increased by transferring the point of contact between the convex surface of the tail or projection and the spring farther from the axis of the weighted arm and nearer to the fixed point of the spring 16. Thereby I am enabled to utilize a scale 23, which has its graduations at uniform distances apart, and to obtain a wide ratio or capacity for the device. The curved surface of the tail or projection of the weighted arm I term for convenience of designation a compensating cam. By means of the said compensating cam I secure the differential spring action which I have explained above. If the said compensating cam were not employed, the action of the spring would vary in the movements of the parts in such manner as to necessitate the use of a scale having graduations at various distances apart.

In the modification which is represented in Figs. tand 5 the upper end of the rod or spin die 5 is prolonged somewhat and is reduced in diameter, the reduced prolongation passy ing through a slot 51, which is made in the yielding arm 17, as shown in Fig. 5. The slot 51 is elongated in the direction of the length of the said arm, so as to permit the move ments of the p arts to take place without 0bstruction. This construction may be adopted, if thought t, to guard against any lateral displacement of the arm 17 and upper cam.,

I claim as my invention- 1. A speed-indicator comprising in combi nation a rotating spindle, a pivoted Weighted arm rotating in unison therewith ,and provided with a compensating cam, a springalso rotating with the said spindle and acting against the said cam, an index or pointer, means to actuate the said index or pointer from the said weightedarm, substantially described.

2. A speed-indicator comprising in combination a rotating spindle, a weighted arm pivotally carried by the said spindle and adapted to swing away from the axis of rotation under the influence of centrifugal force, the weighted arm having a toothed rack and compensating cam, a spring also rotating with the spindle and bearing against the said cam, a loose pinion engaged by the said rack and provided with a cam at the side thereof, the movable piece in contact with the said cam and turning in unison with the spindle with capacity to move endwise thereof, an index, and means to actuate the same from the said movable piece, all substantially asdescribed. 3. A speed-indicator comprising in combi: nation a rotating spindle, a Weight rotat' in unison with the said spindle and .adaplag to move awayfrom the axis of rotation under the influence of centrifugal force, means to oppose the outward movement and return the weight toward the axis of rotation, an arm,

nel

and means intermediate the same and the weight to move the arm, a hub provided with an inclined cam-slot which is engaged by the said arm, and an index connected with the said hub, all substantially as described.

4. A speed-indicator comprising in combination a rotating spindle, aweight supported by the said spindle and adapted to move away from the axis of rotation under the influence of centrifugal force, a spring tending to move the said weight toward the axis of rotation, a cam mounted concentrically with the said spindle, means to operate the said cam from the said weight, the movable piece in contact with the said cam and turning in unison with the spindle with capacity to move endwise thereof, the arm operated by the said movable piece, the hub provided with the inclined cam-slot which is engaged by the said arm, and an index connected with the said hub, substantially as described.

A speed-indicator comprising in combination a rotating spindle, a Weighted arm carried pivotally by the said spindle and adapted to swing away ,from the axis of rotation under the iniiuence of centrifugal force, the said weighted arm having a compensating cam, a spring also rotating with the spindle and bearing against the said compensating cam, the cam mounted concentrically with the said spindle, means to operate the said cam from the said weighted arm, the movable piece in contact with the said cam and turning in unison with the spindle with capacity to move endwise thereof, the arm operated by the said movable piece, a hub provided with an inclined cam-slot which is engaged by the projection of the said arm, and an index connected with the said hub, all substantially as described.

(5. A speed-indicator comprising in combination a rotating spindle, aweighted arm pivotally carried by the said spindle and adapted to swing away from the axis of rotation under the `influence of centrifugal force, the said weighted arm having a toothed rack and a compensating cam, a spring also rotating with the spindle and bearing against the said cam, the loose pinion engaged with the said rack and provided with a cam, a movable piece in contact with the said cam and turning in unison with the spindle with capacity to move endwise thereof, the arm operated by the said movable piece, a hub provided with an inclined cam-slot which is engaged bythe projection of the said arm, and an index connected with the said hub, all substantially as described.

7. In a speed-indicating device actuated by centrifugal force, a weight capable of lateral movement from the axis of rotation, and a restraining-spring whose effective length or tension is changed in proportion to the movement of the weight from the axis of rotation, substantially as described.

8. In a speed-indicator, the combination of a weighted lever moving in a circular path from the axis of rotation and remaining in the same plane of rotation, said lever carrying a segment of a gear, an index-fin ger moved over a scale by the action ofl said weighted lever, and a restraining-spring whose eective length or tension is changed in proportion to the movement of the weighted lever, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

ALBERT L. PARCELLE. 

